Well tool and releasing device therefor

ABSTRACT

Disclosed is an improved well tool that utilizes a unitary gripping member that is pivotally carried by the well tool for movement between a wall engaging position and a retracted position wherein the well tool can be moved through the well bore. A sleeve extends through the gripping member and has a lug thereon that is engageable with the gripping member. A cam member carried by the sleeve or by the gripping member is engageable with both the gripping member and the well bore wall as the sleeve is moved upwardly relative to the gripping member to initiate movement of the gripping member from the well engaging position to the retracted position.

United States Patent [191 Read [4 1 Dec. 18, 1973 WELL TOOL AND RELEASING DEVICE THEREFOR [75] Inventor: Norman Weldon Read, Dallas, Tex.

[73] Assignee: Dresser Industries, Inc., Dallas, Tex.

[22] Filed: May 15, 1972 [21] Appl. No.: 253,087

Attorney-Robert W. Mayer et al.

[57] ABSTRACT Disclosed is an improved well tool that utilizes a unitary gripping member that is pivotally carried by the well tool for movement between a wall engaging position and a retracted position wherein the well tool can be moved through the well bore. A sleeve extends through the gripping member and has a lug thereon that is engageable with the gripping member. A cam member carried by the sleeve or by the gripping member is engageable with both the gripping member and the well bore wall as the sleeve is moved upwardly relative t0 the gripping member to initiate movement of the gripping member from the well engaging position to the retracted position.

15 Claims, 8 Drawing Figures LFMENIEUUEB 18 ms sum 1 (3F 5 FIG. 13

FIG. IA

PATENIEBMs 18 I915 3.779.314 SHZ- 281 3 WELL TOOL AND RELEASING DEVICE THEREFOR BACKGROUND OF THE INVENTION This invention relates generally to improved well tools. More particularly, but not by way of limitation, this invention relates to an improved well too] and to improved releasing devices for such well tools.

This invention contemplates an improvment to gripping members or slips of the type described in U.S. Pat. No. 3,548,936 issued Dec. 22, I970 to Marion D. Kilgore and Robert C. Pumpelly. While the gripping apparatus described in that patent has functioned satisfactorily, it has been found that, and particularly in the larger sizes of such gripping members, difficulty is sometimes encountered in moving the gripping members out of engagement with the wall of the well bore after the tool has been set therein.

Accordingly, it is one object of this invention to provide an improved releasing device for well tools having pivotal gripping members that insure that the gripping members are disengaged from the wall of the well bore to permit removal of the well tool from or movement of the well tool through the well bore.

It is also an object of this invention to provide improved releasing devices for well tool gripping members that are easy and inexpensive to manufacture, that are reliable in operation, and are substantially maintenace free during their service life.

SUMMARY OF THE INVENTION In one aspect, this invention provides improved releasing means for well tool gripping members wherein the gripping members are pivotal on the well tools between retracted and well bore wall engaging positions. The improved releasing means comprises a sleeve carried by the well tool that extends through and is moveable relative to the gripping member, and cam means actuated by movement of the sleeve for simultaneously engaging the gripping member and the wall on the well bore, when the gripping member is in engagement with the wall, to initiate movement of the gripping member toward the retracted position and out of engagement with the wall.

Another aspect of this invention provides an improved well tool for use in well bores comprising an elongated mandrel; a sleeve encircling the mandrel and slideable thereon; a gripping member encircling the sleeve and pivotal thereon between a retracted position and a wall engaging position; abutment means moveable on the mandrel and engageable with the gripping member to pivot the gripping member into the wall engaging position; and, cam means actuated by movement of the sleeve for simultaneously engaging the gripping member and well bore wall to pivot the gripping member toward the retracted position.

The foregoing and additional objects and advantages of the invention will become more apparent when the following detailed description is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1A and 1B, taken together, comprise a view of an improved well tool, constructed in accordance with the invention, that is shown partially in elevation and partially in cross-section.

FIG. 2 is an enlarged fragmentary view of a portion of the well tool of FIG. 1A illustrating, in more detail, the structure of a releasing device that is constructed in accordance with the invention.

FIG. 3 is a fragmentary view, on an enlarged scale, taken substantially along the line 3--3 of FIG. 2.

FIG. 4 is a view similar to FIG. 3, but illustrating the releasing device in another operating position.

FIG. 5 is a view similar to FIG. 3, but illustrating an other embodiment of the invention.

FIG. 6 is a fragmentary cross-section view taken generally along the line 66 of FIG. 5.

FIG. 7 is a fragmentary cross-section view taken generally along the line 77 of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and to FIGS. 1A and 1B in particular, shown therein and generally designated by the reference character 10, is a well tool that is constructed in accordance with the invention. As illustrated, the well tool 10 is shown with its components in the positions that they occupy when the well tool 10 is run into a well bore (not shown).

The well too] 10 includes an upper adapter 12 that is arranged to be connected with a well pipe (not shown) upon which the well too] 10 will be run into the well bore. The adapter 12 is connected near its lower end to a mandrel 14 that extends downwardly through the well tool. The mandrel 14 has a threaded lower end (see FIG. 18) that is adapted to be connected to another well tool (not shown) or to another device in the well bore below the well tool 10.

A sleeve 16 encircles the mandrel l4 and is slideable relative thereto. The upper end of the sleeve 16 extends upwardly into a housing 18 which has a downwardly facing abutment 20 on its lower end.

An upper gripping member 22 is pivotally carried on pins 24 near the lower end of the sleeve 16. The upper gripping member 22 includes wall engaging portions 26 and 28 that are located on diametrically opposed sides and opposite ends thereof. The gripping member 22 also includes an upper surface 30 and a lower surface 32 for purposes that will become more apparent hereinafter.

The sleeve 16 has a lug 34 formed thereon as can be seen in more detail in FIG. 3. The lug 34 projects through an opening 36 formed in the gripping member 22 (see FIG. 2) and carries a cam member 38 that extends upwardly from the lug 34 into a slot 40 formed in the gripping member 22. The cam member 38 is elongated and has a thickness that is greater than the depth of the slot 40 at the surface portion where the member 22 engages the wall so that the cam member 38 can simultaneously engage both the wall of the well bore and the gripping member 22 as shown in FIG. 4.

AS can be seen most clearly in FIG. 3, the cam member 38 is pivotally retained on the lug 34 by pin 42 which also supports a spring 44 that engages the lug 34 and the cam member 38. The spring 44 continually and resiliently urges the cam member 38 toward the gripping member 22. The spring 44 not only aids in retaining the gripping member 22 in its retracted position during traverse of the well tool 10 into the well bore, but also serves to prevent the cam member 38 from inadvertently engaging the wall of the well bore as the well tool is either placed therein or retrieved therefrom.

A lower surface 32 of the slip 22 is engageable, during setting of the well tool 10, with an upwardly facing abutment 46 which forms a portion of an upper thimble 48 of the well tool 10. Located below the upper thimble 48 is a plurality of resilient packer rings or elements 50 which are arranged to be deformed into sealing engagement with the well bore wall when the well tool 10 is set therein. Located below the packing elements 50 is a lower thimble 52 forming a downwardly facing abutment 54 that is engageable with an upwardly facing surface 56 on a lower gripping member or slip 58.

The lower slip 58 is provided with wall engaging portions 60 and 62 and is arranged to be pivoted on the well tool 10 from the retracted position shown in FIG. 18 to a wall engaging position when the well tool 10 is set. A lower surface 64 on the lower gripping member 58 is engageable with an upwardly facing abutment 66 that forms a portion of a drag block assembly 68.

The drag block assembly 68 includes a plurality of drag blocks 70 that are frictionally engageable with the wall of the well bore to resist movement of the well tool 10 therethrough. One skilled in the well tool art will appreciate that the drag block assembly 68 and the lower thimble 52 are moveable relatively together during setting of the well tool 10 after proper manipulation of the J-slot and pin arrangement 72 which is located at the lower end of the drag block assembly 68.

OPERATION OF THE PREFERRED EMBODIMENT The well tool 10 is lowered into the well bore (not shown), and upon reaching the desired location therein is set by manipulating the J-slot and pin arrangement 72 to permit downward movement of the mandrel 14 relative to the drag block assembly 68. When this occurs, the downwardly facing abutment 54 on the lower thimble 52 moves into engagement with the upper surface 56 on the lower gripping member 58. Engagement therebetween causes pivotal movement of the gripping member 58 until the wall engaging portions 60 and 62 thereon engage the wall of the well bore locking the well tool 10 against downward movement.

Continued exertion of a downward force on the well tool 10 moves the lower surface 32 on the upper gripping member 22 into engagement with the upwardly facing abutment 46 of the upper thimble 48. This engagement pivots the upper gripping member 22 toward the set position. Simultaneously, the sleeve 16 moves downwardly moving the lug 34 away from the gripping member 22 to permit pivoting of the slip 22.

The downwardly facing abutment 20 on the housing 18 also engages the surface on the upper gripping member 22 tending to pivot the upper gripping member 22 relatively out of engagement with the wall of the well bore. A force is transmitted through the mandrel 14 into the upper thimble 48 to deform the packing elements 50 as the mandrel 14, housing 18, slip 22 and sleeve 16 move downwardly. When the packing elements 50 have been deformed sufficiently to sealing engage the wall of the well bore, the upper gripping member 22 is positioned so that the wall engaging portions 26 and 28 thereon can engage the wall in tight holding engagement to prevent upward movement of the tool 10 in the well bore. As the sleeve 16 moves downwardly, the lug 34 thereon pulls the cam member 38 downwardly to the position illustrated in FIG. 3 so that the well engaging portions 26 and 28 on the upper gripping member 22 can move into the firm holding engagement with the wall of the well bore. It will also be noted in FIG. 3 that the dimensions of the cam member 38 are such that the cam member 38 engages only the upper gripping member 22 and not the well bore wall. The spring 44 constantly biases the cam member 38 toward the well tool 10 and away from the wall.

When it is desired to remove the well tool 10 from the well bore, the J-slot and pin arrangement 72 is manipulated so that the mandrel 14 can be pulled upwardly relative to the drag block assembly 68. As the mandrel 14 is pulled upwardly, the sleeve 16 is pulled upwardly therewith moving the cam member 38 upwardly along the slot as can be seen in FIG. 4 until the upper end portion of the cam member 38 engages both the wall of the well bore and the upper gripping member 22. When this occurs, a force is exerted on the gripping member 22 in the slot 40 tending to rotate it toward the retracted position. Once the pivotal movement of the upper gripping member 22 has been initiated by the cam member 38, it will be returned to the retracted position as illustrated in FIG. 1A by the spring members carried by the upper gripping member 22 and by the lug 34 engaging the gripping member 22 at the upper end of the opening 36 in the upper gripping member 22.

Simultaneously, the load on the packing elements is released and they resume the positions illustrated in FIGS. 1A and 18. Once the load on the packing elements 50 has been released, continued upward movement moves the shoulder 54 away from the surface 56 on the lower gripping member 58. When this occurs, the lower gripping member 58 is returned to the retracted position of FIG. 18 as a result of the springs caried by the member 58 and due to the engagement between the surface 64 and the shoulder 66 on the drag block assembly 68.

It can be appreciated from the foregoing that the cam member 38 and its arrangement with respect to the upper gripping member 22 provides a means of positively assuring that the upper gripping member 22 will be returned to the retracted position when desired. The components of the well tool 10 are returned to the position illustrated in FIGS. 1A and 1B and the well tool 10 is in condition to be either removed from the well bore or moved to a new location therein.

DESCRIPTION OF THE EMBODIMENT OF FIGS. 5-7

The releasing device illustrated in FIGS. 5-7 is also constructed in accordance with the invention. Unchanged components of the well tool 10 previously described will be referred to by the same reference characters utilized in the previous description.

Referring to FIG. 5, it can be seen that the mandrel 14 extends through a sleeve 116 which is a modified form of a sleeve 16 previously described. An upper gripping member 122 encircles the sleeve 116 and is pivotally supported thereon. The gripping member 122 includes wall engaging portions 128 (only the uppermost wall engaging portion 128 is shown in FIG. 5) and upper and lower surfaces (unnumbered). Also, the gripping member 122 is actuated, that is, moved between the set and unset positions on the well tool 10 as was the gripping member 22.

A lug 134 on the sleeve 116 extends through an opening 136 formed in the gripping member 122. The lug 134 is provided to engage a lower end 137 of a cam member 138. The cam member 138 is carried by the upper gripping member 122 and is slidable relative thereto. To retain the cam member 138 on the upper gripping member 122 and, yet, permit movement of the cam member 138 on the gripping member 122 there is provided a dovetail slot 140 (see also FIGS. 6 and 7) into which a dovetailed lug 142 on the cam member 138 fits.

The cam member 138 has a thickness that is greater than the distance between the gripping member 122 and the wall of the well bore in the area of engagement between the gripping member 122 and the well bore wall so that upon upward movement of the cam member 138, the member 138 simultaneously engages the gripping member 122 and the wall of the well bore to initiate movement of the upper gripping member 122 toward the retracted or unset position.

The aforementioned upward movement of the cam member 138 occurs as a result of the engagement of the lug 134 withthe lower end 137 of the cam member 138. The lug 134 and sleeve 1 16 move upwardly during the act of releasing the well tool as previously described.

In order to maintain the cam member 138 out of engagement with the wall of the well bore when the upper gripping member 22 is set, a compression spring 144 is positioned in a cavity 146 formed between the upper gripping member 122 and the cam member 138. The spring 144 has one end in engagement with the gripping member 122 and the opposite end in engagement with the dovetailed lug 142 that is slideable in the dovetail slot 140. To prevent the cam member 138 from dropping out of the gripping member 122, a screw 148 extends into the slot 140 below the dovetailed lug 142. The screw 148 is provided by way of illustration only and there are many other suitable arrangements that can be utilized to lock the cam member 138 in the gripping member 122. 7

From the foregoing detailed descriptions, it can be appreciated that either embodiment of the releasing devices can be utilized successfully to initiate the movement of the upper gripping members toward the retracted position. It will further be understood that the particular structures of the releasing devices described are presented by way of example only and that many changes and modifications can be made thereto without departing from the spirit and scope of the invention.

I claim:

1. Improved releasing means for well tool gripping members wherein said gripping members are pivotal on well tools between retracted and well bore wall engaging positions, the improvement comprising:

a sleeve carried by the well tool and extending through and moveable relative to said gripping member; and,

cam means moveably attached to said well tool and slideably located between said gripping member and the well bore wall, said cam means adapted to be engaged by movement of said sleeve and slideably wedged between said gripping member and the well bore wall, said cam means thereby disengaging said gripping member from said wall.

2. The releasing means of claim 1 wherein said cam means includes:

an elongated cam member;

means connecting said cam member to said sleeve;

and,

biasing means engaging said cam member and sleeve resiliently urging said cam member toward said gripping member.

3. The releasing means of claim 2 wherein the gripping member includes a slot extending along one surface thereof adjacent the well bore wall, wherein said biasing means urges said cam member into said slot.

4. The releasing means of claim 3 wherein said sleeve includes a lug portion that projects through an opening in the gripping member located at one end of the slot, and wherein said biasing means and pivot means are mounted on said lug portion.

and well bore wall.

6. The releasing means of claim 1 wherein the gripping member has a slot extending along one surface thereof adjacent the well bore wall and wherein said cam means includes:

a cam member slidingly located in said slot, said cam member being engageable with said sleeve; biasing means engaging said cam member and the gripping member for urging said cam member relatively away from the well bore wall; and, retaining means for holding said cam member in the slot.

7. In an improved well tool including a gripping member located for pivotal movement on said tool and having gripping portions engageable with the wall of the well bore when pivoted to hold said tool in a relatively fixed position in the well bore, said tool also including means for causing pivoting of said gripping member toward the wall engaging position, the improvement comprising:

a sleeve moveably carried by the well tool and extending through said gripping member and moveable relative to said gripping member;

said gripping member having a slot in the exterior thereof extending at least partially through one of said gripping portions; and,

cam means moveably attached to said well tool and at least partially disposed in said slot, and slideable therein, said cam means having a portion simultaneously engageable with said gripping member and well bore wall arranged, upon movement of said sleeve and cam means in one direction for forcing said gripping portions out of engagement with the well bore wall.

8. The improved well tool of claim 7 wherein said cam means includes:

a cam member;

means supporting saidcam member on said sleeve;

and,

biasing means urging said cam member toward the gripping member.

9. The improved well tool of claim 6 wherein said cam means includes:

a cam member slidingly positioned in said slot;

biasing means engaging said cam member and gripping member for urging said cam member relatively away from the well bore wall; and,

retaining means for holding said cam member in said slot.

10. The improved well tool of claim 8 and also including a lug portion on said sleeve extending through an opening in the gripping member located at one end of the slot, said lug portion carrying said cam member, pivot means, and biasing means.

11. An improved tool for use in a well bore comprising:

an elongated mandrel;

a sleeve encircling said mandrel and slideable thereon;

a unitary gripping member encircling said sleeve and pivotal thereon between a retracted position and a wall engaging position; I

abutment means moveable on said mandrel and engageable with said gripping member to pivot said gripping member into said wall engaging position; and,

cam means moveably attached to said tool and actuated by movement of said sleeve for simultaneously engaging said gripping member and well bore wall to pivot said gripping member out of engagement with the well bore wall.

12. The improved well too] of claim 11 wherein said cam means includes:

a cam member;

means supporting said cam member on said sleeve;

and,

biasing means resiliently urging said cam member toward said gripping member and relatively away from the well bore wall. 13. The improved well tool of claim 11 wherein said cam means includes:

a cam member slidingly located in the slot; biasing means engaging said cam member and gripping member for urging said cam member relatively away from the well bore wall; and,

retaining means for holding said cam member in said gripping member.

14. The improved well tool of claim 11 wherein:

said gripping member has a slot formed in one surface that is adjacent the well bore wall and an opening extending therethrough at one end of said slot; and,

said sleeve includes a lug portion extending through said opening, said lug portion carrying said cam means.

15. The improved well tool of claim 14 wherein said cam member projects from said lug portion into said slot and has a thickness greater than the depth of at least a portion of said slot whereby movement of said sleeve moves said cam member along said slot into simultaneous engagement with said gripping member and well bore wall when said gripping member is in the wall engaging position to move said gripping member into the retracted position. 

1. Improved releasing means for well tool gripping members wherein said gripping members are pivotal on well tools between retracted and well bore wall engaging positions, the improvement comprising: a sleeve carried by the well tool and extending through and moveable relative to said gripping member; and, cam means moveably attached to said well tool and slideably located between said gripping member and the well bore wall, said cam means adapted to be engaged by movement of said sleeve and slideably wedged between said gripping member and the well bore wall, said cam means thereby disengaging said gripping member from said wall.
 2. The releasing means of claim 1 wherein said cam means includes: an elongated cam member; means connecting said cam member to said sleeve; and, biasing means engaging said cam member and sleeve resiliently urging said cam member toward said gripping member.
 3. The releasing means of claim 2 wherein the gripping member includes a slot extending along one surface thereof adjacent the well bore wall, wherein said biasing means urges said cam member into said slot.
 4. The releasing means of claim 3 wherein said sleeve includes a lug portion that projects through an opening in the gripping member located at one end of the slot, and wherein said biasing means and pivot means are mounted on said lug portion.
 5. The releasing means of claim 4 wherein said cam member has a thickness greater than the depth of at least a portion of the slot in the gripping member whereby said cam member simultaneously engages both the well bore wall and gripping member to move the gripping member out of engagement with the well bore wall upon movement of said sleeve and cam member relative to the gripping member and relatively toward the engagement between the gripping member and well bore wall.
 6. The releasing means of claim 1 wherein the gripping member has a slot extending along one surface thereof adjacent the well bore wall and wherein said cam means includes: a cam member slidingly located in said slot, said cam member being engageable with said sleeve; biasing means engaging said cam member and the gripping member for urging said cam member relatively away from the well bore wall; and, retaining means for holding said cam member in the slot.
 7. In an improved well tool including a gripping member located for pivotal movement on said tool and having gripping portions engageable with the wall of the well bore when pivoted to hold said tool in a relatively fixed position in the well bore, said tool also including means for causing pivoting of said gripping member toward the wall engaging position, the improvement comprising: a sleeve moveably carried by the well tool and extending through said gripping member and moveable relative to said gripping member; said gripping member having a slot in the exterior thereof extending at least partially through one of said gripping portions; and, cam means moveably attached to said well tool and at least partially disposed in said slot, and slideable therein, said cam means having a portion simultanEously engageable with said gripping member and well bore wall arranged, upon movement of said sleeve and cam means in one direction for forcing said gripping portions out of engagement with the well bore wall.
 8. The improved well tool of claim 7 wherein said cam means includes: a cam member; means supporting saidcam member on said sleeve; and, biasing means urging said cam member toward the gripping member.
 9. The improved well tool of claim 6 wherein said cam means includes: a cam member slidingly positioned in said slot; biasing means engaging said cam member and gripping member for urging said cam member relatively away from the well bore wall; and, retaining means for holding said cam member in said slot.
 10. The improved well tool of claim 8 and also including a lug portion on said sleeve extending through an opening in the gripping member located at one end of the slot, said lug portion carrying said cam member, pivot means, and biasing means.
 11. An improved tool for use in a well bore comprising: an elongated mandrel; a sleeve encircling said mandrel and slideable thereon; a unitary gripping member encircling said sleeve and pivotal thereon between a retracted position and a wall engaging position; abutment means moveable on said mandrel and engageable with said gripping member to pivot said gripping member into said wall engaging position; and, cam means moveably attached to said tool and actuated by movement of said sleeve for simultaneously engaging said gripping member and well bore wall to pivot said gripping member out of engagement with the well bore wall.
 12. The improved well tool of claim 11 wherein said cam means includes: a cam member; means supporting said cam member on said sleeve; and, biasing means resiliently urging said cam member toward said gripping member and relatively away from the well bore wall.
 13. The improved well tool of claim 11 wherein said cam means includes: a cam member slidingly located in the slot; biasing means engaging said cam member and gripping member for urging said cam member relatively away from the well bore wall; and, retaining means for holding said cam member in said gripping member.
 14. The improved well tool of claim 11 wherein: said gripping member has a slot formed in one surface that is adjacent the well bore wall and an opening extending therethrough at one end of said slot; and, said sleeve includes a lug portion extending through said opening, said lug portion carrying said cam means.
 15. The improved well tool of claim 14 wherein said cam member projects from said lug portion into said slot and has a thickness greater than the depth of at least a portion of said slot whereby movement of said sleeve moves said cam member along said slot into simultaneous engagement with said gripping member and well bore wall when said gripping member is in the wall engaging position to move said gripping member into the retracted position. 